TITLE:
Corrosion of Snails (Gastropods) in Acidic Environment and Their Protection
AUTHORS:
Rajesh Kumar Singh, Veena Kumari, Deepmala
KEYWORDS:
Corrosion, Snails, Aloe Vera, Carbonic Acid, Potentiostat, Thin Film Formation
JOURNAL NAME:
Journal of Surface Engineered Materials and Advanced Technology,
Vol.9 No.1,
January
31,
2019
ABSTRACT: Snails’ protection is
essential because this species is to maintain a balanced ecology of water
sources. They occur in rivers as well as ponds and balance the pH level of
water. But these sources of water are contaminated by effluents, pollutants,
acid rain, particulates, biological wastes etc. They can change the pH of
water. Water is absorber of carbon dioxide and it converts carbon dioxide into
carbonic. Other above mentioned wastes also increase the concentration of H+ ions in water. They produce hostile environment for snails. The outer part of
snails is made of CaCO3. It produces chemical reaction in acidic medium
and corrosion reaction is accelerated, and thus deterioration starts on the surface of snails.
This medium makes their survival become
miserable. For this work, corrosion of the snails’ study in the pH values of water is 6.5 in H2CO3 environment. The corrosion rates of snails were calculated by gravimetric
methods and potentiostat technique. Aloe Vera was used for corrosion protection
in acidic medium. The surface adsorption phenomenon was studied by Langmuir isotherm. Aloe
Vera formed thin surface film on the interface of snails which adhered with
chemical bonding. It was confirmed by activation energy, heat of adsorption,
free energy, enthalpy and entropy. The results of surface coverage area and
inhibitors efficiency indicated that Aloe Vera developed a strong protective
barrier in the acidic medium.